For an hour and 15 minutes, he paced excitedly, talking nearly nonstop, pointing to charts on a projector, peppering students with questions and leaving them in fits of laughter.

"I was an undergrad at the University of Florida and I used to ride my bike to school and one day there were five guys jogging in place at a red light. I looked over and did a double take and it was Bill Clinton. He used to jog and stop at McDonald's and get an Egg McMuffin."

These days, the guy at the front of the classroom is getting the double takes. At Florida International University in Miami, U.S. Sen. Marco Rubio is professor Rubio.

He teaches political science on Mondays and Fridays, when the Senate is typically off (a workload that provides its own instruction on how Washington operates).

It's a remarkable sight, the 40-year-old Republican hotshot and tea party darling who has hewed to a largely uncompromising script in Washington, striving to provide a balanced take on the political process.

"While earmarks are an important issue to debate, let's not allow them to get out of proportion," Rubio said on a recent Monday, referring to the budget goodies Republicans campaigned against in the 2010 elections. "The truth is, that's not what's running up the national debt."

Rubio does not dish Senate gossip or inveigh against President Barack Obama, as he often does in his other job. His lectures are in every sense academic, students say, only drawn from real-time experience.

As the Stop Online Piracy Act collapsed this spring, Rubio turned it into a lesson on the power of social media, where fears about censorship spread tsunami-like. He has described the behind-the-scenes wrangling that goes into the judicial nominating process. And he has lectured on the use of new media and online fundraising that made his 2010 campaign — which looked quixotic at first — possible.

"I was a little worried at first because I didn't know him," said professor Nicol Rae, who leads the legislative politics class. "It was clear from the first couple of classes that he was going to be very well versed. Students perk up every time Marco rises to his feet."

• • •

The thrust of Rubio's lecture that morning was not whether compromise should be made on weighty issues. Elected amid the tea party wave, Rubio has played a role in the division, serving as a reliable vote against Democratic initiatives. "This is not a policy course," he reminds the 25 students.

His objective is to make them understand the conditions that make "grand bargains" difficult.

That's where Clinton came in. Rubio traced the evolution of compromise under the former president, who faced a Republican Congress angling for a balanced budget, to the modern gridlock fueled by a conflict-hungry 24/7 news cycle and sharper partisan message strategies from both parties.

He spoke of no-drilling postures that may constrain Democrats and antitax pledges that hem in Republicans and why issues that have no chance of passing are put to vote anyway to get people on record and drive an election-year narrative.

On a projector, Rubio displayed the explosive trend of Medicare spending. "On one hand, you can say, 'Hey, we can solve this,' " he said. "On the other hand, you have your pollster saying, 'Boy, this is powerful stuff, man. You can use this to nuke somebody. If somebody tries to change this and we run ads against them, it's devastating.'

"You're a political consultant, you have a client in a tight race, 50-50, their opponent is in favor of changing Medicare. As a political consultant … what's your advice?"

A student in the front shot back, "You're going to tell your candidate, 'Paint this guy as anti-senior, he wants to end Medicare for you and throw you off the cliff.' "

That's what happened in 2011, when congressional Republicans unveiled a plan to alter Medicare. Democrats pounced and produced a misleading ad that showed a grandmother in a wheelchair being pushed off a cliff.

"I really want you to understand the tactical debate," Rubio said, adding that legislative leaders have a harder time delivering a deal because lawmakers increasingly have their own identities.

"If you're a member who got elected because you defeated an incumbent member of your own party in a primary, are you more or less dependent on your party leadership? If you're a member who has a mailing list of 100,000 small-dollar donors around the country, are you more or less dependent on the congressional committee?"

He seemed conflicted, saying the independence is good but the results can be counterproductive, and he asked students to give their views on the final exam.

"How does this republic, which has never been efficient, ultimately solve the problems in this environment where things like the grand bargain may be harder?" he asked. "That's what I want you to start thinking about because that's going to be the dominant theme over the next decade as you become engaged in politics."

• • •

Rubio began teaching at FIU after leaving the Florida Legislature in 2008. (He has a law degree from the University of Miami, but no master's.) The soft landing raised questions, not least over state funding he helped the school secure. The president of FIU's faculty senate complained that Rubio was hired while programs were being cut and 200 jobs eliminated.

Charlie Crist tried to make it an issue in their 2010 U.S. Senate race and Democrats made noise last year when Rubio rejoined the FIU faculty with clearance from the Senate. He makes $24,000 teaching four courses.

"There is just something that doesn't smell right with hiring legislative figures," said FIUphilosophy professor Bruce Hauptli, who raised the concerns in 2008. But he said the financial crunch has eased and acknowledged the buzz on campus. "Now that he's had positions at the state and federal level, there's a sense that political science students really ought to be queueing up to hear what he has to say."

Reviews from the classroom, where laptops sometimes display allegiances to Obama, have been positive. Donovan Dawson, 23, said he disagrees with Rubio politically but having the expertise of an insider was "one of the major attractions of this class."

"We're not just hermits reading from a textbook," Dawson said. "We're actually able to learn from someone who has been in the process and can actually tell us what goes on and what's important and what's not."

There is the cool factor, too: "He's a rising star and could be president someday. It's too early but in a couple years … 2016, 2020."

Rubio, who shows up without a suit and tie, looks the part of a hip academic. "It's almost like The Hangover," he said of the boom-to-bust cycle of the economy. "It was a big, wild spending spree and then all of a sudden you realize it's 5 a.m. and it's like, 'Man, I've got to go to work tomorrow.' "

• • •

In the back of the room, a girl in a Boston Red Sox shirt seemed to lose interest, pulling out an iPhone to text covertly from behind a laptop screen. But the class was winding up and Rubio was soon in a noisy elevator headed for his car.

"It forces me to stop sometimes and analyze things," he said. "I enjoy doing it at this school because a lot of them are like my demographic: young, Hispanic and minority students that care about politics.

"Anybody can tell you so-and-so filed a bill and so-and-so voted against it. What you really need to learn is why did he file the bill and why now, and how come so-and-so voted against it. I want them to be able to read the news and understand what's really going on."